The first cop shot by Brooklyn loner Arthur Alalouf recalled yesterday staring into the gunman’s face as the maniac pointed a shotgun at him – and smiled.

“After he shot me, he was still at the window and he had the rifle pointed at me,” said Emergency Services cop Gregory John, as he walked out of Kings County Hospital.

“I returned fire and notified my team I was hit. He had a grin on his face. It made me mad.”

John was one of the first cops to arrive at Alalouf’s Gravesend house Saturday, and as he walked through the back yard, the gunman blasted at him through a second-floor window.

John was hit in the left shoulder and torso – but his life was saved because he was wearing two bulletproof vests.

That began a six-hour standoff with cops, which ended only after three other officers were wounded and Alalouf was finally killed.

“He’s a very sick man,” John said of the 47-year-old Alalouf, who had amassed an arsenal of guns, knives and swords and threatened to kill cops.

“Thank God no other officers were hurt, thank God no people were killed. He obviously had some problems.”

John and Officer Joseph Ocasio, who was shot in the hand and ankle, left the hospital yesterday. The first thing they did was cross the street to visit fellow cop Jose Guerra at SUNY Downstate Hospital.

Guerra, 33, was hit by shotgun pellets in the face, and had surgery Sunday night to remove at least 10 metal fragments from his right eye.